Rigid endoscopic surgery of brainstem cavernous malformation on the cerebral aqueduct. Case report

Abstract

Cavernous angiomas (malformations) of the brain occur in 0.5% of the population. Most of them are asymptomatic, but due to their anatomical features, namely escape of blood into surrounding tissues, significant neurological symptoms can occur. The deep location of cavernous angiomas in the area of cerebral aqueduct makes surgical intervention difficult. Microsurgical approaches are the gold standard in removal of cavernous angiomas, but they are associated with certain surgical risks in the formation of the surgical corridor. Cavernous malformations in the cerebral aqueduct are a rare subtype. Due to anatomical localization and concomitant obstructive hydrocephalus ІІІ and lateral ventricles, they can be removed by endoscopic frontal transcortical transventricular approach. A 59-year-old patient was diagnosed with cavernous angioma of the brainstem (in the area of cerebral aqueduct) with hemorrhage and the formation of obstructive hydrocephalus ІІІ and lateral ventricles. The operation was performed: removal of the cavernous angioma in the area of cerebral aqueduct by endoscopic frontal transcortical transventricular approach on the right. Additionally, a triventriculocisternostomy was performed. Osteoplastic trepanation with centering at the Kocher’s point in size of 4 × 4 cm and the formation of a free bone flap was performed. The dura mater is cut in an H-shape. Approach to the anterior horn of the right lateral ventricle was performed. An intracerebral retractor was inserted into the anterior horn of the right lateral ventricle. Transforaminal approach to the tuber cinereum was performed - a triventriculocisternostomy was performed. Transforaminal approach to the cerebral aqueduct was performed and the cavernous angioma of the brainstem was removed. In the postoperative period, the patient had a slight deterioration in short-term memory, which regressed 2 weeks after surgery, an increase in oculomotor disorders, in particular persistent diplopia due to moderate paresis of the left oculomotor nerve. Three months after the operation, magnetic resonance imaging of the brain with intravenous contrast enhancement was performed. There are no signs of cavernous angioma. After the operation of frontal transcortical transventricular removal of cavernous angioma in the area of cerebral aqueduct, the compression of the latter was eliminated. Occlusive hydrocephalus regressed, the size of the ventricles decreased. Endoscopic frontal transcortical transventricular approach allows reaching the area of cerebral aqueduct in a less traumatic and minimally invasive manner. This technique is effective due to the low risk of surgical approach complications.